1,25-二羟维生素D3与支气管哮喘

支气管哮喘的免疫机制受多种因素的调节,其中涉及到Th1/ Th2 平衡紊乱等因素.目前已知1,25-二羟维生素D3对于Th1细胞起主导作用的疾病中有着重要意义,但其对于Th2细胞起主导作用的疾病如支气管哮喘的作用目前还没有足够的研究.本文首先描述了1,25-二羟维生素D3对于哮喘气道炎症的影响,然后介绍了其对于CD4+调节T细胞的两个主要亚群:自然调节性T 细胞尤其是获得性调节性T 细胞的作用,接着介绍了1,25-二羟维生素D3对于树突状细胞DC的影响和作用,以及其对于T细胞迁移方面的影响.了解1,25-二羟维生素D3在支气管哮喘中的作用及免疫调节机制,有助于开拓哮喘治疗的新方法.     

1,25(OH)2维生素D3及其受体与支气管哮喘的免疫机制

维生素D作为一种免疫调节剂,在支气管哮喘(简称哮喘)的免疫机制中发挥重要的作用,其中涉及到T细胞的信号转导途径的研究尚不明确.目前已知1,25-二羟基维生素D3[1,25(OH)2 D3]通过与维生素D受体结合发挥免疫调节作用.本文主要综述了1,25(OH)2 D3及其受体介导调节性T细胞在哮喘免疫机制中的作用以及1,25(OH)2 D3发挥生物学效应可能的信号转导途径.了解该免疫机制,对哮喘的防治具有重要的意义.     

调节性T细胞在哮喘治疗中的新进展

支气管哮喘的免疫机制Th1/Th2平衡紊乱受多种因素的调节。该文主要描述了CD4 调节T细胞的两个主要亚群自然调节性T细胞和获得性调节性T细胞,它们分别在抑制自身免疫反应和获得性免疫反应起重要作用。获得性CD4 调节T细胞又可根据分泌不同的细胞因子IL-10和TGF-β,分为Tr1型细胞和Th3型细胞。了解调节性T细胞的免疫调节机制有助于开拓哮喘治疗的新方法。     

维生素D与自身免疫性疾病

1,25-二羟维生素D3[1,25-dihydroxyvitamin D3,1,25(OH)2-D3]是维生素D3的活性形式,自从发现细胞内表达维生素D受体和激活的树突状细胞产生维生素D后,1,25(OH)2-D3的免疫调节作用开始被证实。其主要通过特定的维生素D受体对靶细胞,如T细胞、抗原呈递细胞发挥效应进行调节。本文就1,25(OH)2-D3免疫调节机制,特别是对自身免疫性疾病的免疫调节作用作一综述。     

1,25-二羟维生素D3的免疫调节机理及其应用进展

1,25-二羟维生素D3[1,25(OH)2D3]不仅具有调节钙磷代谢的作用,还可影响多种细胞的生长和分化,具有调节免疫系统的作用.该文综述1,25(OH)2D3的免疫调节机制,为进一步开发更安全有效的类似物,并作为新兴的免疫调节剂应用于临床提供理论依据.     

调节性T细胞及其与支气管哮喘发病的关系

调节性T细胞（regulatory T cells,Treg）是不同于Th1和Th2的具有调节功能的T细胞亚群,它们可分泌免疫抑制因子IL-10和TGF-β,或通过接触抑制等机制,对效应性T细胞产生强大的抑制作用,在多种免疫性疾病包括哮喘中起重要调节作用。本文就Treg的生物学特点、分化与调控及其与支气管哮喘的关系作一综述,以探讨支气管哮喘发病机制的新思路。     

辅助性T细胞在支气管哮喘发病机制中的作用

支气管哮喘(简称哮喘)是一种由多种细胞和细胞因子参与的免疫失衡性的变态反应性疾病,调节性T细胞是近10年来发现的一类在哮喘发病中起重要作用的T淋巴细胞[1].本文研究了哮喘患者Th3等辅助性T细胞亚群的数量和功能的变化,旨在研究Th3等辅助性T细胞在哮喘发病机制中的作用.     

老年原发性高血压患者血清1,25-二羟维生素D_3水平的研究

目的分析老年原发性高血压患者血清1,25-二羟维生素D3水平的变化,探讨1,25-二羟维生素D3水平与高血压的关系。方法选取老年原发性高血压患者98例(高血压组)和健康体检者90例(对照组),检测其血清1,25-二羟维生素D3水平和血浆肾素活性(PRA),并进行比较。结果与对照组比较,高血压组1,25-二羟维生素D3水平明显降低,PRA明显升高(P<0.01)。Pearson相关分析显示,1,25-二羟维生素D3水平与PRA、收缩压、舒张压呈负相关(r=-0.438、r=-0.355、r=-0.655,P<0.05)。logistic回归分析显示,PRA为高血压的危险因素,1,25-二羟维生素D3为高血压的保护因素。结论老年原发性高血压患者血清1,25-二羟维生素D3水平明显低于正常人群。1,25-二羟维生素D3是高血压的保护因素。     

1,25-二羟维生素D3对支气管哮喘大鼠气道炎症和肺内诱导型一氧化氮合酶的影响

目的本文探讨1,25-二羟维生素D3[1,25-dihydroxy vitmin D3,1,25-(OH)2D3]对于支气管哮喘(简称哮喘)大鼠气道炎症和肺内诱导型一氧化氮合酶(induced nitric oxide synthase,iNOS)的影响。方法50只Wistar大鼠随机分为四组:正常对照组,哮喘组,预防处理组和治疗组。用卵蛋白作为致敏原制备哮喘大鼠模型,第一组预防处理组在致敏前三天给予口服1,25-(OH)2D3,共给药3周,第二组预防组则于致敏第1天和第7天给予肌注维生素D3。治疗组则于支气管激发开始前给药处理。应用动物肺功能仪测定大鼠对于乙酰甲胆碱刺激的气道反应性,测定支气管肺泡灌洗液(BALF)细胞总数及嗜酸粒细胞计数和肺组织病理变化。检测肺组织中一氧化氮(NO)含量,iNOS活性和iNOS mRNA表达水平,用免疫组织化学染色方法检测肺组织iNOS的表达并观察iNOS在气道组织分布的改变。结果1,25-(OH)2D3预防及治疗组可减轻BALF中细胞总数及嗜酸粒细胞计数,同时降低肺组织中NO含量、iNOS活性及大鼠肺组织中iNOS mRNA的表达水平。免疫组织化学结果显示,干预组可降低哮喘大鼠气道组织中上皮细胞和巨嗜细胞中iNOS阳性。结论1,25-(OH)2D3可降低哮喘大鼠气道炎症及iNOS表达水平,提示1,25-(OH)2D3对于哮喘可能有潜在的治疗作用。     

CD4+CD25+调节性T细胞在哮喘发生发展中的作用研究进展

支气管哮喘被普遍认为是因Th1／Th2失衡，由过度激活的Th2细胞介导的气道炎症性疾病。然而，Th1／Th2理论并不能充分阐明哮喘的发病机制。近几年来，越来越多的证据显示调节性T细胞在哮喘的发生发展中起到很重要的作用，CD4^＋CD25^＋调节性T细胞作为调节性T细胞的一种亚型成为目前研究的热点。本文就近来对CD4^＋CD25^＋调节性T细胞研究的进展及其与哮喘的关系作一综述。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.